Differential space–time code

Differential space-time codes^1,2 are a way of transmitting data in wireless communications. They are a form of space–time code that does not need to know the channel impairments at the receiver in order to be able to decode the signal. They are usually based on space–time block codes, and transmit one block-code from a set in response to a change in the input signal. The differences among the blocks in the set are designed to allow the receiver to extract the data with good reliability.

There are some non-differential forms which do not need channel knowledge — together with the differential forms, these are termed non-coherent space-time codes.

References

1. V. Tarokh and H. Jafarkhani, "A Differential Detection Scheme for Transmit Diversity," IEEE Journal on Selected Areas in Communications, July 2000.
2. H. Jafarkhani and V. Tarokh, "Multiple Transmit Antenna Differential Detection from Generalized Orthogonal Designs," IEEE Transactions on Information Theory, Sept. 2001.